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Finding the Fourth Proportional to 642.08, 963.16 and 209.28

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Solution

The fourth proportional to 642.08, 963.16 and 209.28 is: 313.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.08 : 963.16 = 209.28 : x
  2. Step 2: Convert to fraction form
    642.08/963.16 = 209.28/x
  3. Step 3: Cross multiply
    642.08x = 963.16 × 209.28
  4. Step 4: Simplify right side
    642.08x = 201,570.12
  5. Step 5: Solve for x
    x = 201,570.12/642.08
  6. Step 6: Final answer
    x = 313.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.